The present invention relates to gas generating systems and, more particularly, to an gas generating system for inflating an inflatable element of a vehicle occupant protection system, the gas generating system incorporating a mechanism for maintaining an average combustion pressure within a predetermined range.
Many solid propellants have an optimum pressure range for combustion. It can be difficult to maintain the gas generating system internal pressure within the optimum pressure range during the majority of the combustion reaction. In addition, low-pressure combustion of the propellant outside of the optimum pressure range may increase the generation of undesirable effluents. Furthermore, operating outside of the optimum combustion range may adversely affect the combustion, thereby abbreviating or shortening the burn of the propellant, or inhibiting sustained combustion of the propellant. It is therefore desirable to maintain the gas generating system internal pressure within the optimum range for combustion of the propellant for as much of the combustion reaction as possible.